There is a correlation between exposure to ultrafine dust and depression and schizophrenia, according to a joint study of 86,634 cases in Seoul from 2003 to 2013 by the Graduate School of Public Health and Seoul National University Bundang Hospital.

(Yonhap)

When the concentration of ultrafine dust reaches 10 micrograms per cubic meter on average for two consecutive days, the number of emergency hospitalizations for mental illness increases by 0.8 percent.

The tendency is especially predominant in warm rather than cold weather, when the level of air pollutants such as carbon monoxide are high, along with ultrafine dust. If air pollutants enter the body or brain, it can cause inflammation or the risk of mental illness.

The mental health risk of ultrafine dust was only observed among those under the age of 65. The research team explained that this age group has longer periods of outdoor activities compared to the elderly.